An electrophotographic image forming apparatus using an electrophotographic process, such as a printer, (hereinafter referred to as an image forming apparatus) forms a latent image by uniformly charging an electrophotographic, photosensitive member serving as an image bearing member and selectively exposing the electrophotographic photosensitive member with light. The latent image is developed with a developer to appear as a developed image. The developed image is then transferred onto a recording medium.
The transferred developed image is subjected to heat or pressure so that it is fixed on the recording medium to form an image, Such image forming apparatuses in the related art involve replenishing developer and maintaining various processing units.
To facilitate the work of replenishing developer and maintenance, part or all of an electrophotographic photosensitive member, a charging unit, a developing unit, and a cleaning unit are disposed in a frame into a cartridge. To allow this process cartridge (hereinafter referred to as a cartridge) to be attached to and detached from an image forming apparatus, a process cartridge system has been employed.
This process cartridge system allows the user to perform maintenance of the apparatus by replacing the cartridge, thus remarkably improving the operability. Such a configuration in which the cartridge can be detachable so that the user can replace the cartridge allows the user to extract the cartridge from the image forming apparatus and to replace it with a new cartridge as a common system.
Shipped new cartridges are each packed in a packing member for protecting the cartridge from vibration and impact during transportation. When installing a new cartridge into an image forming apparatus main body, the user unpacks the packing member, takes the cartridge out of the packing member, and installs the cartridge into the image forming apparatus main body.
Various examples of the packing member that packs a cartridge to protect it from vibration and impact during transportation are disclosed (PTL 1 and PTL 2).
PTL 1 discloses a packing member which is made of a vacuum-formed resin sheet and covers the whole of a cartridge. This packing member has many protrusions and depressions on the surface thereof, with which a cartridge is supported. The packing member fixes the cartridge with flanges of the packing member joined by thermal fusion or the like.